Requirements

This extension requires the
libxml PHP extension. This means that passing in
--enable-libxml
is also required, although this is implicitly accomplished
because libxml is enabled by default.

This extension uses an expat compat layer by
default. It can use also expat, which can
be found at » http://www.jclark.com/xml/expat.html. The
Makefile that comes with expat does not build a library by
default, you can use this make rule for that: